Automatic stack feeder

ABSTRACT

An automatic stack feeder arrangement is provided for delivering large corrugated paperboard sheets to a printer-slotter machine. A stack of the corrugated paperboard sheets is automatically raised to bring the topmost to a desired level where overhanging friction rolls thrust it into parallel friction belts. The conveyed corrugated paperboard sheet is deposited in a hopper on the feed table. The lower set of friction belts is adjustable in working length so as to provide a variable feed table hopper area. The upper set is hinged so that it can be raised away from the lower set.

United States Patent [191 Ward, Jr. et a1.

[ Aug.6, 1974 AUTOMATIC STACK FEEDER [22] Filed: Nov. 23, 1971 [21] Appl. No.: 201,333

Related US. Application Data [63] Continuation-impart of Ser. No. 876,360, Nov. 13,

1969, abandoned.

[52] US. Cl 214/6 D, 214/6 S, 214/8.5 G, 271/76, 271/113, 271/121, 27l/DIG. 7 [5 l] Int. Cl B65h 3/04, B65g 60/00 [58] Field of Search 214/6 D, 6 H, 6 S, 8.5 R, 214/8.5 A, 8.5 G, 6 DS; 27l/D1G. 7, 3, 4, 6, 7, 39, 75, 76, 44, 86, 113, 121; 198/208 [56] References Cited UNITED STATES PATENTS 2,486,415 11/1949 Huntar 271/D1G. 7 3,025,051 3/1962 David et a1. 271/4 Larsson 214/6 D X 3,197,361 7/1965 Schneider 198/208 X 3,254,886 6/1966 Miller 271/3 3,422,969 1/1969 Miller et a1. 214/6 D 3,429,239 2/1969 Murchison et al..... 271/76 X 3,485,489 12/1969 Lindquist 271/6 3,522,943 8/1970 Swanson 271/6 3,617,055 11/1971 Stal 214/6 H Primary Examiner-Robert J. Spar Assistant Examiner-Leslie J. Paperner Attorney, Agent, or FirmWalter G. Finch [57] ABSTRACT An automatic stack feeder arrangement is provided for delivering large corrugated paperboard sheets to a printer-slotter machine. A stack of the corrugated paperboard sheets is automatically raised to bring the topmost to a desired level where overhanging friction rolls thrust it into parallel friction belts. The conveyed corrugated paperboard sheet is deposited in a hopper on the feed table. The lower set of friction belts is adjustable in working length so as to provide a variable feed table hopper area. The upper set is hinged so that it can be raised away from the lower set.

17 Claims, 4 Drawing Figures PATENTEU SHEH 1 [1F 3 WILL/AM E WARD HE/VRY D. WARD GLYDEE. 7I4BER,H

INVENTORS ATTORNEY PATENTED 51974 3.327. 5T6

SHEEI 2 0F 3 'INVENTORS' WILL/AME WARD I HE/VRYD. WARD IE. VIBE/K122 AUTOMATIC STACK FEEDER This application is a continuation-in-part of US. Pat. application Ser. No. 876,360 filed Nov. 13, 1969 for Automatic Stack Feeder, now abandoned.

This invention relates generally to materials handling systems, and more particularly to an automatic stack feeder arrangement for delivering large corrugated paperboard sheets to a printer-slotter machine.

Many machines in the corrugated paperboard box industry are sheet-fed, with the sheets of corrugated paperboard being brought to the machine in stacks which may be from three to seven feet high on roller conveyers or by lift trucks on pallets. In the past, these loads of sheets were transferred into a hopper on the input end of the machine by hand.

With large sheets, of course, this was a very slow process and was limited by the ability of two men to handle the volume and weight of sheets involved. Therefore, this fact has limited the speed of operation of the machine.

It is an object of this invention, therefore, to provide a stack feeder for corrugated paperboard sheets which will accept a full stack beyond the capability of manual handling and automatically feed a sheet therefrom into the hopper of the machine on a demand basis.

Another object of this invention is to provide a machine loader of this character which is adjustable to handle various sizes and thicknesses of corrugated paperboard sheets with a minimum of set-up time.

Yet another object of this invention is to provide a feeder arrangement which can be easily opened and retracted away to provide access to the input side of the feed machine.

Still another object of this invention is to provide a belt conveyer which is telescopic in nature so as to feed corrugated paperboard sheets at a greater or lesser distance from the source, even while the conveyer is operating, if desired.

Other objects and attendant advantages of this invention will become more apparent and understood from the following detailed specification and accompanying drawings in which:

FIG. I is a side elevation of a printer-slotter machine, coupled with the stack feeder with dotted and dashed lines respectively depicting open and expanded positions incorporating features of this invention;

FIG. 2 is a plan view of the arrangement shown in FIG. 1; I

FIG. 3 is a partial front view of the automatic stack feeder pf FIG. 1; and

FIG. 4 is a partial side view of the automatic stack feeder of FIG. 1.

Referring now to the details of the invention as shown in the drawings of FIGS. 1 and 2, reference numeral indicates generally a printer-slotter machine equipped for receiving and operating upon large sheets of corrugated paperboard material, such as a corrugated paperboard B. At the right-hand side of FIGS. 1 and 2, there is shown an elevator or platform lift 12 which may be a commercial item of the hydraulic type adapted for receiving a stack of corrugated paperboard B and automatically transferring it, sheet by sheet, into a hopper area H through the agency of a poweredconveying-and pick-up arrangement to be described hereinafter.

Reference numerals 20, 22, 24, and 26 are, respectively, the press feed unit, the first and second color units, and the creaser slotter unit which process the individual boards B. These standard units 20, 22, 24, and 26 in the industry are mounted slidably upon a base structure 28 to allow the machine to be opened up in either direction for access and set up for the printing, and creasing-slotting functions and to accommodate longer boards. The feed table 18, shown best in FIG. 2, which defines the hopper area H, is extendable as shown by reference numeral 18 and it supports the left end of a plurality of lower transfer belts 30 of a board transfer system 16.

These endless belts 30, which are preferably of cotton belting material, about 3 or 4 inches in width, are driven as shown by the arrows and pass over an end roll 48 of an adjustable backstop on the feed table 18. The outer end of the feed table 18 has a support 47 which positions an idler 46 between the passes of the belts 30.

A belt storage structure 32 receives the other ends of the belts 30 and drives them through the agency of a drive pulley 34. The passage of these belts 30 is first over an idler roll 36 and downwardly to a gravity tension roll 38. Then, in an upwardly direction, the belts 30 go over a fixed idler roll 40 and back downwardly to reeve around a second gravity tension roll 42.

' Moving upwardly, then, the belts 30 change direction over a lower belt feed roll 44 to continue toward the feed table 18 which has mounted thereon, the end roll 48 previously mentioned. Guide tracks 52 and 54 are provided for the respective gravity tension rolls 38 and 42, and they extend vertically within the belt storage structure 32. These guide tracks 52 and 54 captivate, yet give vertical freedom to sliding bearing blocks 56 which journal the rolls 38 and 42.

The upper transfer belts 60 are supported by an open frame 62 which is hinged adjacent the axis of their drive roller 68. The other end of the frame 62 has support brackets 64 which, when the frame is lowered, contact a support bar 66, shown in FIG. 2, on the upper part of the press feed unit 20. An end roller 70, over which the other end of belts 60 pass in the direction of the arrows, is joumaled also on these brackets 64..

A hydraulic cylinder 72 is linked to the frame 62 at one end, and to the belt storage structure 32 at the other, and when operated, lifts athe upper transfer belts 60 away from the lower transfer belts 30 as shown in phantom by the position 62' of the frame 62.

A pair of arms 76 hinged on the belt storage structure 32 extend over the working portion of the elevator 12 and they support a friction feed roll 74 which rotates as indicated by the curved arrow in FIG. 1. Referring now to FIGS. 3 and 4, details of the feed roll 74 and two movable stops are shown, with the latter being coupled together by linkage bars 76, 103, and 104. Turnbuckles 102 are provided for adjusting the width of the gap 105 between the feed roll 74 and the two movable bars 100. The other stop bars 58 are fixed and are curved at the tops. The purpose of the stop bars 100 and 58 is to prevent more than one sheet at a time from entering the press.

This friction feed roll 74, as well as the upper belt drive roller 68 and lower drive pulley and roll 34 and 44, respectively, are operated by a belt drive motor 50, shown in FIG. 2, and are driven at suitable relative speeds. In well-known techniques, this motor 50 may be automatically speeded up or slowed proportion to the rate of feed of the sheets or boards B for optimum speed of the printer-slotter operation.

In operation, a stack of cardboard sheets B are placed onto the platform of the elevator 12. The operator then presses the start switch and the elevator 12 begins to rise. When the top of the stack of cardboard sheets B contacts and pushes up the roll 74, it causes the switch 78 to open and the elevator 12 stops. The roll 74 feeds the cardboard sheets B from off of the top of the stack into the printer one at a time, and in doing so, the roll 74 begins to descend.

When the roll 74 descends far enough to reclose switch 78, the elevator 12 is caused to rise again, thus maintaining a proper feed level. This continues until the stack of cardboard sheets B are all fed into the printer, and the platform of the elevator 12 has now risen to its preset maximum height. This activates the switch 101 which reverses the direction of the elevator 12, sending it to its full down position where it comes to a stop. Another stack of cardboard sheets B are thenplaced onto the platform of the elevator 12 and the sequence is then repeated.

The hinged friction feed roll 74 accommodates a range of l or 2 inches in the operation described. The top edge of the backstop 58, if desired, may be curved so as to guide the topmost sheet B in initial movement.

Now propelled between the moving belts 30 and 60, the sheet B moves until it drops off the end roll 48 of the lower belts-30 into the hopper area H where a small accumulation of boards or sheets B is maintained against a front stop 86 and squarely aligned with a spanker (not shown). A reciprocating feed bar 90 or equivalent feed mechanism of the vacuum type moves under the lowermost sheet B, engages it, and thrusts it into the nip rolls 88 of .the press feed unit 20.

For adjustments of the hopper area H to accommodate the various sheet sizes, a feed screw 82 is operated by a drive unit 84 which moves the backstop 80 upon the feed table 18. The printer slotter may be opened between sections 20, 22, 24, 26 for set-up, thereby moving the feed table to position 18. In either case, the reservoir of belting in the storage structure 32 provides or absorbs the extension or retraction thus caused in the lowerextended belting. I

By slidably mounting the elevator 12 as well as the board transfer system 16 upon the base structure 28, it is possible to raise or remove the frame 62 and reduce the horizontal extension of the lower transfer belt 30 to a minimum or remove it completely. With the elevator 12 and transfer system then moved to the left so as to abutt the feed table 18, the rollers 74 and 68 will discharge boards directly into the hopper H.

The electrical control system is designed to maintain a low reservoir of sheets in hopper H until the stack is almost completely used up. The final foot, or so, of stack can be fed in at high speed so as to accumulate a larger reservoir in the hopper H while the elevator 12 is automatically returned to its lowered position to accept another load. If the load in hopper H gets low before a new stack is started, the printer slotter can be slowed down to allow more time for re-charging the elevator 12.

Two elevators 12 can be used, in tandem, to provide a more continuous loading operation. One elevator 12 can feed while the second elevator 12 is being charged. If desired, this loading system can be used to charge the hopper H at right angles rather than from the front, as shown.

It is also possible to have two elevators 12, one on each side ofthe machine, to load alternately from one side, then the other for more continuous operation.

If desired, the elevators 12 can be positioned on wheels so that they can be moved into and out of position in the automatic feeder system as required.

Also, if required, the automatic stack feeder system as shown in FIGS. 1 and 2 can be re-arranged so that lower belt feed roll 44 is superimposed on end roll 48, with the result that the belt storage structure 32 can be eliminated. The automatic stack feeder system can, therefore, be made more compact and shortened where space is of the essence.

In FIG. 1, a curved gate is shown at the upper end of the vertical plate or backstop 58 and below the friction feed roll 74. There are instances where this curved gate can be made straight, if the design of the automatic stack feeder system requires a straight gate for the passage of the corrugated paperboards B into the feeder system.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. An automatic stack feeder system for individual delivery of sheets of material from a stack to a predetermined position, comprising:

means for vertically elevating a stack of sheets of material;

means for moving horizontally the successive topmost sheets of said stack of sheets;

means for preventing movement of more than one of said sheets from said stack of sheets at a time;

a mechanism for transferring the sheets successively moved from said stack of sheets, the mechanism comprising an upper endless belt means and a lower endless belt means positioned adjacently beneath the upper endless belt means, the sheets being transferred between said upper and lower endless belt means;

means for receiving and vertically restacking said sheets transferred between said belt means from said stack of sheets;

' means including a rigid extensible device for adjust-' ing the extension of said lower endless belt means toward as well as away from said receiving and restacking means;

tension means including plural rollers for storing a part of said lower endless belt means on all said adjustments of said extension of said lower endless belt means; and,

feed means for delivering successively the bottommost sheets from said restacked stack of sheets to said predetermined position.

2. An automatic stack feeder system as recited in claim 1, wherein said means for preventing movement of more than one sheet of said sheets from said stack of sheets consists of a gate structure.

3. An automatic stack feeder system as recited in claim 2, wherein said gate structure is self-aligning between said means for successively moving said topmost sheets of said stack of sheets and said means for transferring said sheets successively moved from stack of sheets.

4. An automatic stack feeder system as recited in claim 2, wherein said gate structure is curved.

5. An automatic stack feeder system as recited in claim 1, wherein said tension means includes at least one movable idler roller having a vertical guide track and at least one fixed idler roller.

6. An automatic stack feeder system as recited in claim 5, wherein said upper endless belt means is supported by a roller at each extreme of the extension thereof and is pivoted upwardly about the roller supporting said extension opposite said overhanging exten- 510R.

7. An automatic feeder as recited in claim 6, a rotary powered device for moving all said endless belt means, moving means, rollers, and elevating means, and a powered member for said upward pivoting of said upper endless belt means.

8. An automatic feeder as recited in claim 6, wherein said means for successively moving said topmost sheets of said stack of sheets is yieldably mounted.

9. An automatic stack feeder system as recited in claim 8, wherein said yieldable mounting for said means for successively moving the topmost sheets includes a supporting arm pivotal about the roller about which said upper endless belt means is pivotal, and a roller positioned at the end of said supporting arm for engagement with the topmost sheets of said stack of sheets, with said means for preventing movement of more than one sheet of said stack of sheets being vertically positioned below said supporting arm for restraining sheets below the topmost sheet from moving.

10. An automatic stack feeder system as recited in claim 5, and additionally a roller for supporting a portion of said lower endless belt means positioned beneath said roller about which said upper endless belt means is pivotal, thereby forming a nip aligned to receive successive sheets of material moved by said moving means for successively moving said topmost sheets, and switch means responsive to the position of said topmost sheet for controlling said elevator means.

11. An automatic stack feeder system for individual I tension means for tensioning and storing a part of said lower belt means, a length of said upper endless belt means overhanging by extending beyond the extension of said lower endless belt means in the direction of said transfer, the tension means including plural rollers for storing a part of said lower endless belt means on all said adjustments of the extension of said lower endless belt means;

hopper means at said extension of said lower endless belt means for receiving and vertically restacking said sheets so transferred; means including a rigid extensible device for adjusting the extension of said lower endless belt means toward or away from said hopper means; and,

reciprocating feed means for delivering successively the bottom-most sheets from said restacked sheets to said predetermined position.

12. An automatic stack feeder system as recited in claim 11, wherein said tension means includes at least one movable idler roller having a vertical guide track and at least one fixed idler roller.

13. An automatic stack feeder system as recited in claim 12, wherein said upper endless belt means is sup ported by a roller at each extreme of the extension thereof and is pivotal upwardly about said roller supporting the extension opposite said overhanging exten- SlOl'l.

14. An automatic stack feeder system as recited in claim 13, and additionally a rotary powered device for moving all said endless belt means, moving means, rollers, and elevator means, and a powered member for said upward pivoting of said upper endless belt means.

15. An automatic stack feeder system as recited in claim 14, said moving means for'successively moving the topmost sheets is yieldably mounted.

16. An automatic stack feeder system as recited in claim 15, wherein said yieldable mounting for said moving means for successively moving the topmost sheets includes a supporting arm pivotal about the roller about which said upper endless belt means is pivotal, and a shield vertically positioned below said supporting arm for restraining sheets below the topmost sheet from moving.

17. An automatic stack feeder system as recited in claim 16, and additionally a roller supporting a portion of said lower endless belt means positioned beneath said roller about which said upper endless belt means is pivotal, thereby forming a nip aligned to receive successive sheets of material moved by said moving means for successively moving said topmost sheets, and switch means responsive to the position of said topmost sheet for controlling said elevator means. 

1. An automatic stack feeder system for individual delivery of sheets of material from a stack to a predetermined position, comprising: means for vertically elevating a stack of sheets of material; means for moving horizontally the successive top-most sheets of said stack of sheets; means for preventing movement of more than one of said sheets from said stack of sheets at a time; a mechanism for transferring the sheets successively moved from said stack of sheets, the mechanism comprising an upper endless belt means and a lower endless belt means positioned adjacently beneath the upper endless belt means, the sheets being transferred between said upper and lower endless belt means; means for receiving and vertically restacking said sheets transferred between said belt means from said stack of sheets; means including a rigid extensible device for adjusting the extension of said lower endless belt means toward as well as away from said receiving and restacking means; tension means including plural rollers for storing a part of said lower endless belt means on all said adjustments of said extension of said lower endless belt means; and, feed means for delivering successively the bottom-most sheets from said restacked stack of sheets to said predetermined position.
 2. An automatic stack feeder system as recited in claim 1, wherein said means for preventing movement of more than one sheet of said sheets from said stack of sheets consists of a gate structure.
 3. An automatic stack feeder system as recited in claim 2, wherein said gate structure is self-aligning between said means for successively moving said topmost sheets of said stack of sheets and said means for transferring said sheets successively moved from stack of sheets.
 4. An automatic stack feeder system as recited in claim 2, wherein said gate structure is curved.
 5. An automatic stack feeder system as recited in claim 1, wherein said tension means includes at least one movable idler roller having a vertical guide track and at least one fixed idler roller.
 6. An automatic stack feeder system as recited in claim 5, wherein said upper endless belt means is supported by a roller at each extreme of the extension thereof and is pivoted upwardly about the roller supporting said extension opposite said overhanging extension.
 7. An automatic feeder as recited in claim 6, a rotary powered device for moving all said endless belt means, moving means, rollers, and elevating means, and a powered member for said upward pivoting of said upper endless belt means.
 8. An automatic feeder as recited in claim 6, wherein said means for successively moving said topmost sheets of said stack of sheets is yieldabLy mounted.
 9. An automatic stack feeder system as recited in claim 8, wherein said yieldable mounting for said means for successively moving the topmost sheets includes a supporting arm pivotal about the roller about which said upper endless belt means is pivotal, and a roller positioned at the end of said supporting arm for engagement with the topmost sheets of said stack of sheets, with said means for preventing movement of more than one sheet of said stack of sheets being vertically positioned below said supporting arm for restraining sheets below the topmost sheet from moving.
 10. An automatic stack feeder system as recited in claim 5, and additionally a roller for supporting a portion of said lower endless belt means positioned beneath said roller about which said upper endless belt means is pivotal, thereby forming a nip aligned to receive successive sheets of material moved by said moving means for successively moving said topmost sheets, and switch means responsive to the position of said topmost sheet for controlling said elevator means.
 11. An automatic stack feeder system for individual delivery of sheets of material from a stack to a predetermined position, comprising: means for vertically elevating a stack of sheets; roller means for horizontally moving the successive top-most sheet of said stack of sheets; upper endless belt means positioned adjacently to the roller means; lower endless belt means positioned adjacently beneath the upper endless belt means, the upper and lower endless belt means acting to horizontally transfer between them said sheets successively moved from said stack of sheets; tension means for tensioning and storing a part of said lower belt means, a length of said upper endless belt means overhanging by extending beyond the extension of said lower endless belt means in the direction of said transfer, the tension means including plural rollers for storing a part of said lower endless belt means on all said adjustments of the extension of said lower endless belt means; hopper means at said extension of said lower endless belt means for receiving and vertically restacking said sheets so transferred; means including a rigid extensible device for adjusting the extension of said lower endless belt means toward or away from said hopper means; and, reciprocating feed means for delivering successively the bottom-most sheets from said restacked sheets to said predetermined position.
 12. An automatic stack feeder system as recited in claim 11, wherein said tension means includes at least one movable idler roller having a vertical guide track and at least one fixed idler roller.
 13. An automatic stack feeder system as recited in claim 12, wherein said upper endless belt means is supported by a roller at each extreme of the extension thereof and is pivotal upwardly about said roller supporting the extension opposite said overhanging extension.
 14. An automatic stack feeder system as recited in claim 13, and additionally a rotary powered device for moving all said endless belt means, moving means, rollers, and elevator means, and a powered member for said upward pivoting of said upper endless belt means.
 15. An automatic stack feeder system as recited in claim 14, said moving means for successively moving the topmost sheets is yieldably mounted.
 16. An automatic stack feeder system as recited in claim 15, wherein said yieldable mounting for said moving means for successively moving the topmost sheets includes a supporting arm pivotal about the roller about which said upper endless belt means is pivotal, and a shield vertically positioned below said supporting arm for restraining sheets below the topmost sheet from moving.
 17. An automatic stack feeder system as recited in claim 16, and additionally a roller supporting a portion of said lower endless belt means positioned beneath said roller about which said upper endless belt means is pivotal, thereby forming a nip aligned to receIve successive sheets of material moved by said moving means for successively moving said topmost sheets, and switch means responsive to the position of said topmost sheet for controlling said elevator means. 